summaryrefslogtreecommitdiff
path: root/gnu/pipe2.c
diff options
context:
space:
mode:
Diffstat (limited to 'gnu/pipe2.c')
-rwxr-xr-xgnu/pipe2.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/gnu/pipe2.c b/gnu/pipe2.c
new file mode 100755
index 00000000..059d8039
--- /dev/null
+++ b/gnu/pipe2.c
@@ -0,0 +1,141 @@
+/* Create a pipe, with specific opening flags.
+ Copyright (C) 2009, 2010 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3, or (at your option)
+ any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+#include <config.h>
+
+/* Specification. */
+#include <unistd.h>
+
+#include <errno.h>
+#include <fcntl.h>
+
+#include "binary-io.h"
+
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Native Woe32 API. */
+
+# include <io.h>
+
+#else
+/* Unix API. */
+
+# ifndef O_CLOEXEC
+# define O_CLOEXEC 0
+# endif
+
+#endif
+
+int
+pipe2 (int fd[2], int flags)
+{
+#if HAVE_PIPE2
+# undef pipe2
+ /* Try the system call first, if it exists. (We may be running with a glibc
+ that has the function but with an older kernel that lacks it.) */
+ {
+ /* Cache the information whether the system call really exists. */
+ static int have_pipe2_really; /* 0 = unknown, 1 = yes, -1 = no */
+ if (have_pipe2_really >= 0)
+ {
+ int result = pipe2 (fd, flags);
+ if (!(result < 0 && errno == ENOSYS))
+ {
+ have_pipe2_really = 1;
+ return result;
+ }
+ have_pipe2_really = -1;
+ }
+ }
+#endif
+
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Native Woe32 API. */
+
+ /* Check the supported flags. */
+ if ((flags & ~(O_CLOEXEC | O_BINARY | O_TEXT)) != 0)
+ {
+ errno = EINVAL;
+ return -1;
+ }
+
+ return _pipe (fd, 4096, flags);
+
+#else
+/* Unix API. */
+
+ /* Check the supported flags. */
+ if ((flags & ~(O_CLOEXEC | O_NONBLOCK | O_TEXT | O_BINARY)) != 0)
+ {
+ errno = EINVAL;
+ return -1;
+ }
+
+ if (pipe (fd) < 0)
+ return -1;
+
+ /* POSIX <http://www.opengroup.org/onlinepubs/9699919799/functions/pipe.html>
+ says that initially, the O_NONBLOCK and FD_CLOEXEC flags are cleared on
+ both fd[0] amd fd[1]. */
+
+ if (flags & O_NONBLOCK)
+ {
+ int fcntl_flags;
+
+ if ((fcntl_flags = fcntl (fd[1], F_GETFL, 0)) < 0
+ || fcntl (fd[1], F_SETFL, fcntl_flags | O_NONBLOCK) == -1
+ || (fcntl_flags = fcntl (fd[0], F_GETFL, 0)) < 0
+ || fcntl (fd[0], F_SETFL, fcntl_flags | O_NONBLOCK) == -1)
+ goto fail;
+ }
+
+ if (flags & O_CLOEXEC)
+ {
+ int fcntl_flags;
+
+ if ((fcntl_flags = fcntl (fd[1], F_GETFD, 0)) < 0
+ || fcntl (fd[1], F_SETFD, fcntl_flags | FD_CLOEXEC) == -1
+ || (fcntl_flags = fcntl (fd[0], F_GETFD, 0)) < 0
+ || fcntl (fd[0], F_SETFD, fcntl_flags | FD_CLOEXEC) == -1)
+ goto fail;
+ }
+
+# if O_BINARY
+ if (flags & O_BINARY)
+ {
+ setmode (fd[1], O_BINARY);
+ setmode (fd[0], O_BINARY);
+ }
+ else if (flags & O_TEXT)
+ {
+ setmode (fd[1], O_TEXT);
+ setmode (fd[0], O_TEXT);
+ }
+# endif
+
+ return 0;
+
+ fail:
+ {
+ int saved_errno = errno;
+ close (fd[0]);
+ close (fd[1]);
+ errno = saved_errno;
+ return -1;
+ }
+
+#endif
+}